The present invention relates to apparatus for filling containers with liquid product. More specifically, the invention relates to apparatus for filling bottles with pharmaceutical preparation, such as a solution for intravenous administration. The invention also relates to filling containers with a liquid product with the aid of apparatus, and more specifically to filling bottles with a pharmaceutical preparation for intravenous administration.
When filling bottles and other types of container with pharmaceutical products, a complete filling process will include the following process stages:
1. A container washing stage. PA1 2. A container sterilizing stage. PA1 3. A bottle filling stage. PA1 4. A container sealing stage. PA1 5. A filled container sterilizing stage. PA1 a) a generally horizontal manifold or branched pipe which is connected to a storage container for the delivery of product to be poured into the containers, and to a collecting container for collecting product that is not fed into the containers, and which manifold is provided with at least one outlet which leads to a connected volume container for introducing product into the product containers, wherein the volume containers are designed with a determined, adjustable volume which corresponds to the product volume to be introduced into each product container, and wherein the outlet ends of the volume containers are provided with point valves which adjust the outflow of product to the product containers, and wherein the outlet orifice of the manifold leading to the volume containers discharges on a level which lies above the bottom level of the manifold; PA1 b) a product return line for returning product from the collecting container to the storage container; PA1 c) sensor means which monitor the highest and the lowest permitted liquid levels in the manifold; PA1 d) connections to a source of gas under overpressure, this gas functioning to expell liquid product from the volume containers to the product containers and to blow residues of product from the point valves, so as to transport remaining liquid product from the manifold to the collecting container and to transport liquid product from the collecting container to the storage container; PA1 e) a conveyor for advancing product containers to be filled along a linear conveyor path and for delivering the filled product containers to a container sealing apparatus; and PA1 f) a program mechanism which receives impulses from the sensor means which detect the liquid level in the manifold, and also from sensor means which detect the positions of the product containers on the conveyor, and on the basis of these impulses functions to control the setting of valves in product and gas conduits and also to control the movement of the conveyor. PA1 a) feeding the product containers into a conveyor and advancing the containers along a linear path, wherein movement of the containers is interrupted when the containers are located in a predetermined filling position; PA1 b) feeding the liquid product from a storage container to a generally horizontal manifold to which there is connected at least one outlet of a volume container from which the product is passed to the product containers, the volume containers being designed with a determined, adjustable volume which corresponds to the product volume to be poured into each product container, and wherein the manifold outlet leading to the volume containers discharges at a level which lies above the bottom level of the manifold, and wherein the outlets of respective volume containers are closed by means of openable point valves; PA1 c) subsequent to having filled the volume containers and the manifold to a level which lies above the level of the manifold outlet to the volume containers, interrupting the delivery of product from the storage container and leading away that part of the liquid which does not enter the volume containers but remains in the manifold to a product collecting container and then passing this remaining liquid product back to the storage container through a return line; PA1 d) opening the point valves at the outflow ends of the volume containers so that liquid product will flow out into the product containers, whereafter a stream of gas is passed through the volume containers and the point valves to purge the containers and said valves from product residues; PA1 e) restarting the conveyor and conveying the filled product containers along a path which is connected to a product container sealing apparatus, such that the filled product containers will be accelerated smoothly to a speed which is adapted to the container advancing speed of the container sealing apparatus, and feeding the containers into and sealing said containers in said apparatus; and PA1 f) repeating steps a) to e) in sequence a desired number of times.
During these various process stages, the containers are exposed to the risk of contamination by bacteria and other microorganisms, the greatest risk in this regard being in stage 3, in which the bottle are filled with liquid product. The risks are greater in this particular process stage, because product tends to splash as it is poured into the bottles and also during the subsequent transportation of the bottles to the stopper fitting section of the apparatus, i.e. the bottle stoppering unit, and also because of subsequent dripping of product from the filling nozzles used. This splashing and subsequent dripping of the liquid product generates the risk of a thin liquid film forming between the stopper and the glass surface at the bottle neck, and therewith form a culture substrate for bacterial growth, which can spread to the product in the bottle concerned. Such bacteria growth can also occur when a layer of liquid is formed between the stopper and the capsule placed around the stopper. The actual container-filling stage is therefore a highly critical stage of the complete process.
The development of machines for filling containers with solutions for parenteral administration, and then particularly for intravenous administration, began in the 1950s, although the use of low capacity apparatus began somewhat earlier. At the present time, apparatus capable of filling containers with intravenous solutions at a rate of 4,000-5,000.times.100 ml/h are commercially available.
In the majority of cases, these known machines are based on the use of electronic control and operating units and are complicated and less reliable in use than is desired. Because of the electronics, the apparatus is highly sensitive to the stresses and strains to which a filling machine is subjected under normal operating conditions. Spillage can occur during a firing operation, and it is often necessary to thoroughly clean the machine, using large quantities of water and/or steam in the process. This can readily cause malfunctioning of the electronic devices, resulting in interruptions in machine operation.
Another drawback is found in the transportation of a filled bottle to the downstream stoppering unit. More often than not, the bottles are stationary as they are filled, but must then be moved to a bottle stoppering unit. This bottle transfer often involves abrupt acceleration of bottle movement, so as to adapt movement of the bottles to the rate at which the bottles are transported in the bottle stoppering unit, which often operates at a relatively high speed. Such abrupt acceleration of the bottles presents considerable risk of product splashing from the bottles.